“Plans of de facto partition of Syria exist. We know about it and will ask our American colleagues how they do imagine all this,” Lavrov said during a speech at “Leaders of Russia” contest.

He also said Americans were changing their stance about the reason for their presence in Syria.

“Americans seem to have abandoned assurances given to us that the only purpose of their presence in Syria is to defeat terrorists.

“Now they say this presence will remain until they are convinced that Syria has begun a sustainable process of political settlement, the result of which will be regime change,” he said.

Syria has been locked in a vicious civil war since early 2011, when the Bashar al-Assad regime cracked down on pro-democracy protests -- which erupted as part of the "Arab Spring" uprisings -- with unexpected ferocity.

Since then, more than a quarter of a million people have been killed and more than 10 million displaced across the war-battered country, according to the UN.

The Syrian Center for Policy Research, however, put the death toll from the conflict at more than 470,000 people.